CVE-2026-62799: CWE-122: Heap-based Buffer Overflow in Microsoft Windows 11 version 26H1
Heap-based buffer overflow in Windows SMB Client allows an authorized attacker to elevate privileges locally.
AI Analysis
Technical Summary
This vulnerability involves a heap-based buffer overflow in the Windows SMB Client on Windows 11 version 26H1 (build 10.0.28000.0). An attacker with local authorization can exploit this flaw to elevate their privileges, potentially gaining higher-level access than intended. The vulnerability is tracked as CVE-2026-62799 and is classified under CWE-122 (Heap-based Buffer Overflow). Microsoft has published an official security update to remediate this issue.
Potential Impact
Successful exploitation of this vulnerability allows an authorized local attacker to elevate privileges, potentially leading to full system compromise or unauthorized access to sensitive resources. The CVSS score of 7.8 reflects high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
An official fix is available from Microsoft. It is strongly recommended to apply the security update provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62799 to remediate this vulnerability.
CVE-2026-62799: CWE-122: Heap-based Buffer Overflow in Microsoft Windows 11 version 26H1
Description
Heap-based buffer overflow in Windows SMB Client allows an authorized attacker to elevate privileges locally.
CVSS v3.1
Score 7.8high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability involves a heap-based buffer overflow in the Windows SMB Client on Windows 11 version 26H1 (build 10.0.28000.0). An attacker with local authorization can exploit this flaw to elevate their privileges, potentially gaining higher-level access than intended. The vulnerability is tracked as CVE-2026-62799 and is classified under CWE-122 (Heap-based Buffer Overflow). Microsoft has published an official security update to remediate this issue.
Potential Impact
Successful exploitation of this vulnerability allows an authorized local attacker to elevate privileges, potentially leading to full system compromise or unauthorized access to sensitive resources. The CVSS score of 7.8 reflects high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
An official fix is available from Microsoft. It is strongly recommended to apply the security update provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62799 to remediate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-07-14T21:08:07.965Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62799","vendor":"Microsoft"}]
Threat ID: 6a7b5818bf8831d539156009
Added to database: 08/11/2026, 17:12:56 UTC
Last enriched: 08/11/2026, 21:28:05 UTC
Last updated: 08/12/2026, 03:01:12 UTC
Views: 3
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